MEET BOSTON BLACKIE
Robert Florey, Director
These six snapshots are all from the same scene which lasts about 15 seconds.  The scene is toward the middle of the film.  Although Schlitzie's role is commonly said to be that of "Princess Betsy",  I believe the inside talker is saying  "Princess Fifi".
Courtesy Turner Classic Movies
1941
"... and this little lady is Princess Fifi.  She's baffled the greatest scientific minds in the medical world.  Some believe she is half woman and half bird, while others are too amazed to make any diagnosis whatsoever.  She was found  playing in a pelican's nest high in the cliffs of Afghanistan, and when they tried to take her down she screamed something like this [two short whistles].  We feed her nothing but raw eggs and angle worms and there's a standing reward of twenty-five hundred dollars, think of it folks, twenty-five hundred dollars for every man, woman and child that can penetrate the mystery of this unusual freak of nature.  Now ladies and gentlemen, I'm going to pass among you some postcards of the little Princess.  They can have them no other place in the world but here.  They're only ten cents, one tenth of a dollar."
"Meet Boston Blackie" was the first in a series of fourteen Boston Blackie films by Columbia Studios that ran from 1941 - 1949.  Schlitze "played the part" of Princess Fifi, a pinhead at a Coney Island sideshow. He didn't really do anything in the film, just kinda stood there in the background.
   Schlitze is pictured at right with the principal actors in the film, Chester Morris and Rochelle Hudson.
   Morris, after over 100 films and TV appearances, died at age 69 of a barbituate overdose. Hudson, with as many appearances to her credit, died in 1972, a year after Schlitzie passed.
But is Schlitzie really in this photo?  Look at his left hand.  It's being cupped by another hand and it's not that of Chester Morris. Also, Schlitzie's head is not casting a shadow and Morris and Hudson are not looking at him. This is clearly a photo fake.
For some unknown reason Schlitzie in this photo is identified as "Julius the pinhead" at www.highbeam.com
(above) from "Famous Monsters" (magazine), May 1981.  Since he's wearing the same costume as the character in the film I assume it was taken on the set. What looks like a little hat on his head is actually a ribbon tied around his topknot.
(right) A copy of the actual Call Service Cast sheet identifying the "Bird Woman" as "Schlitzzy Metz".
courtesy National Film Information Service, Margaret Herrick Library